Just want to mention the Universal Binary Format (UBF) suggested by
Joe Armstrong (one of the poeple behind Erlang). It is meant to be an
alternative to XML. Here is a pointer:
http://www.sics.se/~joe/ubf/site/home.html
Best, Micke 

On 7/4/05, Lex Spoon <lex at cc.gatech.edu> wrote:
> 
> > I have an object that I want to serialize in XML now this object
> > contains a date object
> > of course I can save it explicitly as a string and do a readFrom....
> > But I wanted to know if there is a more advance serialization process.
> 
> My usual pattern for this is to put xmlForExport methods on every class
> I want to be able to save, and then have decodeXML: methods on the class
> side of these same classes.  Finally, I add a master decodeXML: method
> somewhere in my system that looks at the tag and then calls decodeXML:
> on the proper class.  At first, the master decodeXML: method has a long
> list of ifTrue:'s in it to select the class to restore, but if the
> system lasts long enough I'll end up making a Dictionary that maps XML
> tag names into class objects.
> 
> Actually, usually I don't use XML per se if I am just doing Squeak work.
>  I convert to trees of arrays, analagous to s-expressions, and I don't
> convert small objects such as integers, floats, and points -- classes
> that are extremely unlikely to change for the duration of time that my
> external files should last.  I then export and import the array trees
> using SmartRefStream.  This is Squeak-specific, but it is a little more
> convenient and it does not cause problems with cross-version
> compatibility.
> 
> 
> There is a meme going around that you should use an automatic serializer
> for this kind of thing, but if you do so then in practice you sacrifice
> cross-version compatibility.  That is, if you use an automatic
> serializer -- be it SIXX, SmartRefStream, or ImageSegment -- then files
> you create today will probably not be loadable after your software has
> evolved for several months.  The problem is that you will tend to
> refactor your code as it evolves, creating new classes and eradicating
> old ones, and thus the serialized files will specify classes that no
> longer exist.
> 
> 
> There is substantial room for improvement in this pattern, but it is
> somewhere to start.  I yearn for the day that serialization is treated
> more seriously, the day when software folks lose their fanatacism with
> low-level file formats (XML) and silver bullets (automatic
> serialization).
> 
> 
> -Lex
> 
>